[Evolution in the knowledge on fiber]

Fiber is an essential nutrient in a healthy diet, contributing to health maintenance and preventing the occurrence of different disease. The classification of fiber according to its degree of fermentation within the large bowel categorizes it into two different types, completely fermentable fiber and partially fermentable fiber. The level of fermentability of each fiber will give it characteristic properties. Besides the known effects of fiber on transit and bowel movement regulation, the recent advance on the knowledge on the metabolism of some fermentable fibers, such as inulin, fructo-oligosaccharides, and galacto-oligosaccharides, has shown its prebiotic effect. Because of this fermentation, short chain fatty acids with important colonic and systemic functions are produced. Therefore, it is essential to perform a balanced diet with adequate fiber consumption.